Power transmission and change speed clutch mechanism therefor



1953 T. lAVELLI 2,647,598

POWER TRANSMISSION AND CHANGE SPEED CLUTCH MECHANISM THEREFOR Filed Nov. 4, 1949 2 Sheets-Sheet 1 IN V EN TOR. 7:970 fare/. 11

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/7 fro WWI 6T Aug. 4, 1953 V 2,647,598

POWER TRANSMISSION AND CHANGE SPEED CLUTCH MECHANISM THEREFOR Filed Nov. 4, 1949 2 Sheets-Sheet 2 IN VEN TOR. 7- 77a [d e/AI Patented Aug. 4, 1953 POWER TRANSMISSION AND CHANGE SPEED CLUTCH MECHANISM THEREFOR.

Teno Iavelli, Detroit, Mich., assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application November 4, 1949, Serial No. 125,574

8 Claims.

This invention relates to variable speed power transmissions for automotive application and to the change speed clutch mechanism therefor.

More particularly the invention relates to improvements in blocker ring type of centrifugal pawl clutches and in the structure for energizing the blocker ring thereof and is especially concerned with such improvements as applied to clutch mechanism having in drive series a blocker ring type of centrifugal pawl clutch and a toothed blocker ring type of interengageable multi-tooth clutch and which improvements are intended to better facilitate a synchronized shift of the multi-tooth clutch and to prevent tooth damage as when starting the Vehicle from restwith a high idle engine and without disengagement of the master clutch.

Mechanism of the latter character is shown and described in the application of Bucy et al., Serial No. 16,214, filed March 22, 1948. According to that disclosure, engine drive of the toothed blocker ring is obtained through a chain of structure including a conical frictional drive between the pawl blocker and pawl receiving shell, and a second conical friction drive between the shell and the toothed blocker ring, one or more fiat finger type springs being utilized for facilitating the friction drives.

Although this arrangement has given satisfactory results in most cases, the use of exceptionally strong finger springs to effect the frictional drive has been found desirable and these even when made of steel could not always be relied upon to operate for extended periods without fatigue or to provide a-uniform distribution of pressure. Moreover, when separate finger springs were used for each blocker, that for the centrifugal clutch pawl blocker was located between this blocker and the pawl carrier and the heavy pressure of this spring against the blocker tended to cock the latter and cause jamming at the conical friction surfaces. Moreover, the springs were located where they were subject to the action of relatively rotating surfaces and this adversely affected them. I have discovered that if the energizing pressure for the pawl blocker is transmitted to it through the pawl shell, cooking and jamming is, avoided since the blocker obtains a solid backing against the pawl carrier. Moreover, the use of coil compression springs makes available the requisite degree of pressure without fatigue and the spring structure may be arranged to avoid the action of relatively rotating surfaces.

An object of this invention is therefore, to provide a simple and effective structure for driv- 2 ing the toothed blocker ring of a multi-tooth clutch in a transmission arrangement providing a centrifugal pawl clutch drivingly ahead of the multi-tooth clutch.

Another object is to provide a simple and effective structure for establishing frictional drive between the pawl blocker and pawl receiving shell of a centrifugal pawl clutch, which drive is not susceptible to jamming or cooking of the working parts.

Still another object is to provide a coil compression spring arrangement for imparting uniform circumferential thrust between the pawl blocker and pawl receiving shell of a centrifugal pawl clutch sufficient to impart and maintain a frictional drive between these elements, and wherein the springs are not subject to fatigue or the action of relatively moving surfaces.

These and other objects of my invention will, become more apparent from the following de scription when taken in conjunction with the accompanying drawing wherein:

Figure 1 is a longitudinal sectional elevation view of the clutch mechanism of my invention;

Figure 2 is a transverse sectional view taken at 2--2 in Figure 1; and

Figure 3 is a transverse sectional view taken at 33 in Figure 1.

Referring to the drawing wherein similar reference characters are used to designate corresponding parts of the structure, Figure 1 shows my invention as applied to a change speed transmission such as shown and described in the said copending application of Bucy et al., and reference is hereby made to said copending application for any structure or controls referred to in the subject description but not shown in the drawing.

As seen in Figure l a drive shaft I 0 extends rearwardly into a housing or casing 12 of the transmission where it is rotatably supported by a ball bearing l4 and is formed With a main drive pinion 16 adjacent its inner end. Formed on the rearward end of the shaft Ill adjacent the pinion I6 is an annular extension IS on which is carried and to which is splined as at I9 a pawl carrying member 20 of a centrifugal type pawl clutch generally designated by the letter G. The member 20 is also carried by a sleeve 20A which together with a washer 2| and snap ring 22 holds this member in position on the shaft I0. The annular extension 18 of the shaft I0 provides a bore 23 which journals, by a bearing 24, the forward end 26 of a driven shaft 28.

The drive pinion I6 is arranged in constant mesh with a gear forming part of a countershaft cluster gear 32, which is carried for rotation on a countershaft 34 supported in the casing I2. The cluster includes a second or intermediate speed ratio drive pinion 3% which is arranged to be in constant mesh with the second speed gear 38 rotatably journalled on the shaft 28 between the shaft 28, enlargement 30 and a washer 40 held endwise by a snap ring 4!.

The gear 33 has a set of integral external clutch or drive control teeth 42, adapted for interengagement with a set of internal clutch or drive control teeth 33 of a manually shiftable clutch sleeve or member generally designated by the letter F, which is adapted to be shifted rearwardly, axially of the shaft 28 from its neutral position shown in Figure l, to engage the clutch teeth 42 or alternatively to be shifted forwardly to engage a set of integral external clutch or drive control teeth 44 of a floating centrifugal clutch pawl receiving shell generally designated by the numeral 46. The sleeve F is movable by a suitable yoke member, not shown.

The clutch sleeve F is slidably carried on a hub generally designated by the numeral 43. The hub 48 has a rearwardly extending annular portion 50 splined as at 52 to the shaft 28. The hub 48 is provided with external splines or teeth 54 spaced circumferentially to provide recesses or splineways to receive the internal teeth 43 of the sleeve F.

The shaft 23 is preferably provided with an annular bearing sleeve 56 on which the centrifugal clutch shell 0 is rotatably journalled and axially movable. Moreover, the enlargement 39 of the shaft 28 rearwardly of the hub 48 is preferably formed with circumferentially spaced external cam faces 58 providing an inner race to engage the rolls 00 of an over-running roller clutch generally designated by the letter J. The gear 38 has a forwardly extending annular portion 62 which carries the clutch teeth 52 and is provided with a smooth internal annular face 84 which serves as the outer race or runway for the rollers of the clutch J. The rollers 58 are carried in a cage 06 which has radially outwardly extending projections or tabs 68, one being shown, received in longitudinal slots formed in the periphery of the hub 58. These projections or tabs 68 are engageable with certain camming v teeth 00 of the clutch sleeve F as more specifically described in said Buoy et al. application for controlling the cage 50 such that the roller clutch is operative to transmit power only when the sleeve F is in its forward position engaged with the clutch teeth M. Compression springs 12 are seated in recesses of the tabs 68 and bear against the tabs and side walls of the hub slots to bias the rollers 60 in a direction to move them into a locked-up driving position between the cams 58 of the shaft 28 and the outer race 0d of the gear 38 to establish a one-way drive from the gear 38 to the shaft 28 when, as previously stated, the clutch sleeve F is in its forward position engaged with the teeth 44 and there is a tendency of the gear 38 to rotate faster than the shaft 28 in a forward direction. Upon any tendency of the gear 38 to slow down below the speed of the shaft 28 the clutch J will permit overrunning of the shaft 28 with respect to the gear 33. In the neutral position of the sleeve F shown in Figure 1 no drive is possible in either direction through the clutch J. In the rearward or two-way second speed position of the sleeve F the control cage 63 is still maintained by the sleeve F in a position 4 to prevent drive through this overrunning device.

The gear 38 is provided at the forward end of its extension 32 with a cone-shaped or frustoconical surface M. A similar surface i6 is provided at the rearward end or annular portion it of the pawl shell 46. Journalled on each of the surfaces 14, 16 are blocker or balking rings 80 and 82 respectively, provided with pointed or keystone-shaped blocker synchronizing teeth 84, 8t alignable with slots El of the clutch sleeve F.

Ring is urged into frictional drive connection with the surface 14 of the gear 38 by a finger spring 88 positioned between the hub 48 and the hub portion 90 of the ring 80. A similar spring 92 is located between the hub 48 and the hub 94 of the ring 82. The teeth 84, 86 of the rings 00 and 82 respectively, are also engaged in slots 08 of the hub 48 which provide a limited relative rotation of these rings relative to the hub 48 and hence also with respect to the sleeve F such that when the relative speeds of the sleeve F and gear 38 are asynchronous the teeth 34 of the ring 80 will tend to block rearward shift of the sleeve F until the speeds of the clutch sleeve F and the gear 38 become synchronous.

The teeth 86 of the ring 82 similarly serve to block forward shift of the clutch sleeve F when the sleeve F and the shell 46 are rotating asynchronously.

The centrifugal pawl clutch G comprises a pawl carrier 20 driven by the shaft l0, a plurality of pawls, two being shown, each generally designated by the numeral I00, and a floating pawl receiving shell member 46 which, as previously stated, may be drivingly connected to the shaft 28 by shifting the clutch sleeve F forwardly to its overrunning second drive position into engagement with the clutch teeth 44 of the shell. When thus engaged the clutch sleeve F releases the roller cage 66 of the roller clutch J to permit drive of the shaft 28 through the rollers 60 by the gear 38.

The pawls I00 are adapted for outward movement oppositely to one another in response to centrifugal force occasioned by rotation of the carrier 20 to engage slots or windows I02 provided in the annular portion I04 of the floating shell 46 to establish a two-way direct drive between the shafts l0 and 28 when the sleeve F is clutched with the teeth 44 of the shell 40. Preferably a plurality of pawl receiving windows I02 are provided, which number is also preferably a multiple of the number of pawls, eight windows being here shown.

Each pawl has a clutching head portion M5 for engagement with the windows I02 and a tail portion Hill, which acts as a guide for the head of the opposite pawl. Moreover, the pawls are maintained in their disengaged position below a. predetermined speed of rotation of the carrier 20 by a normal retracting bias applied by control or governor springs l08, which oppose the centrifugal tendencies of the pawls in the speed range where disengagement of the pawls is desired. The clutch G is also provided with a member or ring generally designated by the numeral Hi9 having a double function, first that of serving as a blocker or balk ring for preventing engagement of the pawls with the windows I02 of the shell member 46 until the rotative speeds of the pawls and shell are synchronous, and secondly of providing a drive connectionfor the shell 48 and blocker member 82 to inhibit establishment of a drive from the engine through the overrunning clutch J when the vehicleis ata speed and forward shift of the sleeve F is either accidentally or deliberately attempted without first releasing the master clutch.

The member I09 is in theform of a frustoconical ring, the outer surface of which is cut with a continuous oil groove formed by a fine pitch thread and arranged to frictionally contact asmooth complementary internal conical surface H2 provided on theannular forwardly projecting portion I 04 of the clutch shell 46 just rearwardly of the windows I02. The ring I09 is circumferentially recessed at its inner periphery, as seen in Figure 3 at IZI and I24, to provide a pair. of diametrically opposite'radially inwardly directed lugs II l, IIEiwhich are stepped to form inner and wider outer lug portions. The base or outer lug portion of the lug IIII has side faces H6, land that of the lug lib side faces IIB, H9. The side faces III IIB connect with a circumferential land I of the recess I2! to provide a circumferential step. Similarly the side faces I ll, II9are connected by a circumferential land I22 of the recess I24 to provide a circumferential step. These lands I20, I20 are at the same radial distancefrom the axis of rotation. Each lug has a further pair of steps. Thus lug I I has astep I26 formed by a side face I2l and a land I28, and a step I30 formed by a side face I-tl and a land I32. Similarly the-lug II5 has a step I34 formed by a side face I35 and a land I36 and a step I38 formed by a side face I39 and a land I60. The ring I09 may be split to provide a slight outward spring effect so as to facilitate establish ment of a normal light frictional contact between the conical surfaces H0, H2.

A feature of the invention resides in the arrangement and combination of structure for energizing the friction drive between the shell member 06, and blocker ring I09 and in the-provision of .means for establishing drive of the blocker 62 from the drive shaft I0. Thus drive between the shaft I0 and the ring I09 may be effected as hereinafter described between pins I66, I62 located on the pawls I00 at the same radial distance, and rigidly fixed in the rearward side faces thereof so as to project rearwardly into the vertical plane of the ring I06 with which they are adapted to become drivingly engaged. Drive between the ring I66 and the shell 46 is accomplished through the friction connection at the conical surfaces H0, H2, this friction connection being energized by a plurality, four being shown, of coil compression springs I64, which as seen in Figures 1 and 2, are carried in lateral recessesor bores I 66 in the shell 66 and have their rearward ends bear against a ring I66 which is seated in a recess IIil of the hub 36 and has its rearward surface H2 in contact with the thrust taking and bearing surface Il l of this recess of the hub 48 with which it may have relative rotation.

In order to prevent any side buckling of the springs it such as might be caused by relative motion between the shell member 46 and a surface against which the rearward ends of the springs are'in contact, the ring I63 is by preference provided with forwardly projecting protuberances or post-like members I76, two being shown, which are operably engaged in recesses I10 of the shell d6 to thus prevent relative rotation between the ring I68 and the shell 46. The projections III; of the ring I68 have a slight out-= wardly converging taper to facilitate assembly with the recesses I'IB of the shell 46.

ti-a1 and the vehicle is at a standstill with the It will be observed that the springs I64 exert a forward bias against the shell 46, which is transmitted to the contacting conical surfaces H0, H2, the pressure exerted between these surfaces being sufficiently strong to permit drive of the shell 46 by theblocker ring I09 when drive is effected between the carrier I0 and the ring I09 through the pawl pins I60, I62. The above described construction makes it possible to obtain 7 pressure contact between the surfaces I I0, I I2 of any desirable value without danger of fatigue.

It also effects an even distribution of the lateral bias and inhibits cocking or jamming of the shell 36 or blocker ring I09 during operation, whether energized by the springs I64 alone or as amplified by forward movement of the sleeve F when effect ing engagement with the teeth 44, it being noted in this connection that the blocker ring I09 receives a solid backing by engagement of its forward end face I79 with the face I60 of the carrier I8. Manifestly, the spring 92 applies a forward bias to the tooth blocker 82 to effect a drive engagement between this member and the shell 46 i such that when the shell member is driven from the carrier it also, by reason of this latter fric-.

tional drive engagement, effects a drive of the blocker 82.

During asynchronous rotation of the pawls and I lands IMP-I22 may, if desired, function as outer diameters measured on the same arc as these lands. This permits the pawls to readily engage the nearest window under all relative positions of k the pawls and windows.

When the centrifugal pawls I00 are below their engaging speed, the pins I60, I 62 will be engaged with one or the other of the inner portions of the lugs I I 4, I I 5 depending upon the operating conditions prevailing in the transmission, and

will prevent engagement of the pawls with the shell 46 even when the pawls reach their engag ing speed until such time as the pins becomes disengaged from these inner portions of the lugs.

When the clutch sleeve F is positioned in neuengine idling, the pins I60, I62 will be engaged with the said faces I35, I 3| respectively of the lugs II5, I I4 so'as to rotatably drive the blocker member or ring I09 in the direction of rotation of the pinion I6. Engagement of the pawls at this time will be prevented by the faces I36, I32v of thelugs which will also prevent ratcheting of the pawls, clearance being maintained at thisv 46 and the friction connection between the blocker ring 82 and the shell 46, these parts will also tend to rotate with the ring I09. The teeth 66 of the blocker rin 82 will, therefore, be rotated tothe limit of the lost motion connection ,provided between the teeth 86 and the slots 96 in I acrea e 7 the lrub 48* so -as:-to-bebrought into blocking relationship with theteeth- Moi the SISEVGF'.

If the master clutch of the vehicle be disengaged by depressing the clutch pedal and the clutch sleeve F- be moved forwardly to establish secondspeed drive ratio through the overrunning clutch-J engagement between the teeth of the sleeveFand blocking ring 82 will transmit increased-pressure at theconical surface I6--ofthe shell46 and conical surface iID- of the ring lllll 'to bring the shell 46- to-a standstill (thesleeve'F being-atthis time stationary) and-the te'eth-43 ofthe-sleeve Fwill thereupon pass between the teeth fifi of theblocker ring land into engagement with the teeth 44 of the shell 46; During'this' movement of thesleeve Finto engagement with the teeth 44; the projection 68 of'the overrunning'clutch J will bepermitted tdbe urged by the spring m -into clutch lockup position-whereby drive may be transmitted from the gear 38 "through the overrunning clutch J to" the" shaft 261' By reason of the engagement between-the clutch sleeve F and the teeth 44,

drive will also-beimpressed upon the shell 4G-' through 'the hub 4B; sleeve F, and teeth 44.

Should for-some reason the driver deliberate- 1y or accidentally shift the sleeve forwardly underthe aforesaid conditions without, however, having-releasedthe master clutch, it would be impossible to synchronize the shell member 45 with'ith'e sleeve-F to permitengageinent between the=teeth43= of the sleeve and the teeth 44 of thesshe'lli'member 4& because increased pressure betweenthe blocker ring 82- and the-shell 46 will alsobe impartedxto the friction connection IIG, IIQCrbetween the shellinember dfi'and the pawl blocker ring Iilfilsince the ring I99 is in drive-relationship-with the pinion It at this time. Hence asynchronousiconditions will bemaintained and engagement of. the sleeve F'with the teeth 44, and-of:theoverrunning clutch J will be prevented thereby: avoiding tooth breakage or other damage;': especially should the engine be operatingz at thisrtime.undera high idle condition.- It is to be noted that the length of'the shell slots or windows WZ-"parallel to the axis of rotation oflthe clutch G is sufficient totallow for a-substantialforward axial-movementtof theshell 46" without interferingwith thepawls I68, I62. The constructionprovides for some permissible forward: movement of the shell member 46' when pressurezis-appliedbetween the hub and the shell by theasprings I 64';

Engagement of'the sleeve F with the teeth 44 willalso'be prevented if as. shift from two-way second-speed: ratio position is attempted: while the. vehicle v is undergoing drive if the master clutch is not maintainedreleased at the time the sleeveE passesthrough the neutral position.-

Assuming thatsthe clutch sleeve F has been shiftedforwardly into engagement with-theteeth;

44iandthe, master clutchhas been engaged,- drive will be established as previously indicated, in At. this.

thecpawlswill drive the blocker ring I09 at the speediorthe-pinion I d thering I89 slipping relativeto .theshell member 45. As 'the vehicleis acceleratedrin this overrunning second speed ratio drive, centrifugal force will tend to move thepawls Ifidoutwardly against the: retracting effeohof their governor springs Iilllcbut they will bei-preventedfrom engaging" the. shell by the lands IBZ' 'an'd" I 36 of" the ring" I09; Once the speed ofthe vehicle is at "or -above the engaging speedofth'e pawls -I fillfactionp upon the: part of the d-river-to*relax-pressure on the accelerator pedal to move the-throttlein-a closingdirection' will cause the engine to decelerate and slow down-rotation of the pawl carrier I8. When thee-peed of theca-rrier I 8 becomes synchronized withthe speed of the shell member 46, or stated otherwise; whenthe' speeds of the pawl carrier 1 8 and shell member- 4-6 CIOSST each; other the ring I09 'wi11* no longer be driven by" the pawls' but will be driven by the shellmem'ber'46*through its friction connection therewithand relative motion will take placebetweenythe ring I 09 "and to slide ofi the lands' I36, I32 respectively and into the recesses I21, I24 respectively provided by the lands "I20, I22'of the'ring I691 Should the-pawls at this moment be alignedwith the shellwindows-- I82; engagement therebetween' WiITimmediately take place to establish a two'- direct-d-rivebetween the shafts II] and23. However, shouldthe pawls and windows be misaligned, the pins I Ell; I 62 will move through the recesses --I 2 I I 24 while *thepawls- I t ll rub "againstthe-annular surface I89 of' the'shell until'the' next nearest windows of the-shell become aligned with the pawls whereupon engagement will take It is to be notedthat the-lands-JZ'G, I22

place; are ofesufli'cient length to" permitthis engagement-to talieplacez Oncethe pawls 'are engaged, the driver may against depress the accelerator and" the vehicle willibe driven indirect drive until such time as its speed. drops below the -engaging speed of" the pawls i518 whereon the governor springs" Iiit'of the pawls will urge thepawls-to-retract"and such will loccur 'immediately thedriving pressure between the pawls Iildand-the'shell 46 is sufiiciently relieved;

Ass soonz as thepaw-ls become disengaged, the

pinsrlfim. I62 will again assume-theposition in thez'recesses I34;- ISD respectively; and drive' the blocker ring I 09 111 the manner previously described.

Under icoaststorqueconditions at 'orabove the engaging speed 'of F the paWls-in overrunning sec ond": speediratiodrive, the shaft 28' will become the driver and--the-tendency will be for the shell. 85 todrive the blocker ring I 09 through'its.

frictionxconnection' I I8, I'm-such that the'ring lilfirwill now rotatably-leadthe pawl carrier I8; Under."these conditions the faces I21, I28and I39} 149:0ftthe inner portions of the lugs I 44; I I5.

the-ringd 99 and w-ill slide'ofi'" the "lands 7 I 28, M0 and: enter the recesses-providedby the lands I20,

I222. Thereafter the pawls-willbecome engaged withith'e shell' windows -as=-soon as theseelements havebecome aligned with each other.

From the-above description-it willbe seen that I have-provided: a transmission structure providing a: novel blocker energizing and drive arrangcment-for-the clutch mechanismithereof that is believed; free of jamming and-cocking and that facilitates clutch engagement" without clash orv ttooth damage.

adapted to be drivingly connected with the latter,

centrifugal pawl means operable to drivingly connect said shell member and said driving means, a pawl blocker ring journalled by said shell member for frictional drive therewith and adapted for drive connection with said pawl means, and a plurality of coil compression springs operable upon said shell for energizing said friction drive between said ring and shell member, said ring being intermediate said shell member and pawl means and said pawl means taking the thrust reaction of said springs.

2. In a power transmission, driving means, driven means, a freely rotatable shell member coaxial with said driving and driven means and journalled on the latter, releasable means for drivingly connecting said shell member and driven means, centrifugal pawl means operable to drivingly connect said shell member and said driving means, a pawl blocker ring journalled by said shell member for frictional drive therewith, means for drivingly connecting said ring and pawl means, and a, plurality of coil compression springs operable upon said shell for energizing said friction drive between said ring and shell member, said ring being intermediate said shell member and pawl means and said pawl means taking the thrust reaction of said springs.

3. In a power transmission, driving means, driven means, a freely rotatable shell member coaxial with said driving and driven means and adapted to be drivingly connected with the latter, centrifugal pawl means operable to drivingly connect said shell member and said driving means, a pawl blocker ring journalled by said shell member for frictional drive therewith, means for drivingly connecting said ring and pawl means, an abutment on said driven means, and a plurality of coil compression springs operable between said shell and said abutment for energizing said friction drive between said ring and shell member, said ring being intermediate said shell member and pawl means and said pawl means taking the thrust reaction of said springs.

4. In a power transmission, driving means, driven means, a freely rotatable shell member coaxial with said driving and driven means and adapted to be drivingly connected with the latter, centrifugal pawl means operable to drivingly connect said shell member and said driving means, a pawl blocker ring journalled by said shell member for frictional drive therewith, said ring having an end face arranged to abut said pawl means, means for drivingly connecting said ring and pawl means, a stop on said driven means, a spring thrust ring in abutment with said stop and drivingly connected with said shell member and a plurality of coil compression springs operable between shell member and thrust ring for energizing said friction drive between said blocker ring and shell member.

5. In a power transmission, a drive shaft, a driven shaft, a freely rotatable shell member journalled on one of said drive and driven shafts, centrifugal pawl means operable to drivingly connect said shell member and said drive shaft, a hub member fixed to said driven shaft for rotation therewith, means for drivingly connecting said hub and shell members, a frusto-conical blocker ring journalled by said shell member for frictional drive therewith, means for drivingly connecting said blocker ring and pawl means, a spring thrust ring in abutment with said hub member and drivingly connected with said shell member, and a plurality of coil compression springs operable between said shell member and said thrust ring for energizing the drive between said blocker ring and shell member.

6. In a power transmission, a drive shaft; a driven shaft; a freely rotatable slotted shell member journalled on one of said drive and driven shafts; centrifugal pawl means operable to drivingly connect said shell member and said drive shaft, said means including a pawl carrier having an end face, and a pawl rotatable with said carrier and engageable with a slot of said shell for establishing said drive connection; a pawl blocker ring rotatable with said carrier and rotatable within limits relative thereto, said blocker ring having a conical frictionface for coacting with a complementary conical friction face on said shell member for supporting said ring and to establish a friction drive therebetween when these friction faces are energized and having an end face engageable with said end face of said carrier for maintaining said ring centered relative to said shell; a spring abutment rotatable with said shell member; and a plurality of coil compression springs operable between said shell member and abutment for transmitting energizing pressure through said shell member to said coacting friction faces and as an incident thereto effect engagement of said end faces of said blocker ring and said carrier.

7. In a power transmission, a rotatable drive shaft; a rotatable driven shaft; a freely rotatable shell member journalled on said driven shaft; centrifugal pawl clutch means operable to drivingly connect said shell member and drive shaft, said centrifugal clutch means including a pawl carrier rotatable with said drive shaft and an end face on said carrier, and a pawl driven by said carrier; a hub member secured to said driven shaft for rotation therewith and having a predetermined position axially thereof, said hub member having an end thrust taking face; means carried by said hub member for drivingly connecting said hub member and shell member; a pawl blocker ring having a conical friction face coactable with a complementary friction face on said shell member for establishing a friction drive therebetween and having an end face engageable with said end face of said carrier when said ring is urged in the direction of said carrier; means on said pawl and blocker ring providing for rotation of said blocker ring with said carrier and for limited relative rotation between them; a spring backing element drivingly connected with said shell member for rotation therewith and having an end face coactable with said end thrust face of said hub member when said backing element is urged in the direction of said hub member; and a plurality of coil compression springs operably arranged between said shell member and said backing element, said springs being operable to transmit energizing pressure through said shell member to said coacting friction faces and as an incident thereto urge the said end faces of blocker ring and carrier into engagement and the said end face of said spring backing element into engagement with the thrust taking face of said hub.

8. In a power transmission, a rotatable drive shaft, a rotatable driven shaft; a freely rotatable shell member journalled on said driven shaft, said shell member having a set of clutch teeth and having a pair of conical friction faces; centrifugal pawl clutch means operable to drivingly connect said shell member and drive shaft; said centrifugal clutch members including a pawl carrier rotatable with said drive shaft, an end face on said carrier, and a pawl rotatable with said carrier; a hub member secured to said. driven shaft in predetermined position for rotation therewith, said hub member having an end thrust taking face; an axially shiftable member carried by said hub member and shiftable axially into and out of engagement with the said clutch teeth of said shell; a balking ring rotatable with the shiftable member and rotatable within limits relative thereto, said balking ring having a friction face for coacting with one of said conical friction faces of said shell member; a pawl blocker ring rotatable with said carrier and rotatable Within limits relative thereto, said blocker ring having a conical friction face for coacting with the other of said conical friction faces of said shell for supporting said blocker ring and establishing a friction drive connection between said blocker ring and shell member and said blocker ring having an end face engageable with said end face of said carrier when said blocker ring is urged in the direction of said carrier; a spring backing ring having an end face for coacting with said end thrust face of said hub member when said element is urged in the direction of said hub member, said ring having a pair of lateral lugs receivable in recesses in said shell member for establishing a drive connection between this element and said shell member; and a plurality of circumferentially spaced coil compression springs operably disposed between said shell member and backing ring and seated in recesses in said shell member, said springs being operable to transmit energizing pressure through said shell member to said coacting friction faces of said shell member and said blocker ring and as an incident thereto bias the said end faces of said blocker ring and carrier into engagement and the said end face of said backing element into engagement with said thrust taking face of said hub member and there being spring means for energizing the coacting friction faces of said balking ring and shell member.

TENO IAVEILI.

References Cited in the file of this patent UNITED STATES PATENTS 

